JPH088291A - Wire bonding equipment - Google Patents

Abstract

(57) [Abstract] [Object] The present invention realizes a wire bonding apparatus that does not require clamp adjustment work. [Structure] When the lead frame is a magnetic material, the die pad and the inner lead of the lead frame are attracted to the surface of the heat adapter by the magnetic force of the electromagnet. As a result, the lead frame can be accurately clamped on the surface of the heat adapter without any defect even if the wind clamper, which requires skill in adjustment work, is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding apparatus, and is suitable for application to, for example, an ultrasonic wave combined thermocompression bonding wire bonding apparatus.

[0002]

2. Description of the Related Art Conventionally, in a wire bonding apparatus of this type, as shown in FIG. 4, a lead frame 4 on which an IC chip is mounted is sandwiched between a wind clamper 2 and a heat adapter 3 from above and below, and an inner lead and a die pad are formed. It is designed to suppress floating.

Incidentally, the wind clamper 2 is attached to the wind clamper attaching portion 5 by the attaching screw 6,
By the vertical movement of the wind clamper mounting portion 5, the fixing operation and the releasing operation of the lead frame 4 are repeated. That is, the lead frame 4 is clamped and fixed by the downward movement of the wind clamp attachment portion 5, and the lead frame 4 is opened by the upward movement of the wind clamper attachment portion 5.

[0004]

However, the fixing state of the wind clamper 2 with respect to the wind clamper mounting portion 5 cannot be determined only by fixing with the mounting screw 6, and there is a problem that the lead frame 4 floats due to insufficient clamping. Atsuta Insufficient clamping in this way causes defects such as defective wire bond joining and wire neck breakage at the time of product completion. Therefore, in addition to the mounting screw 6, an angle adjusting screw 7 is used to adjust the height so that the surface of the wind clamper 2 and the surface of the heat adapter 3 are parallel to each other, so that a sufficient clamp can be obtained.

However, even if the angle adjusting screw 7 is used, it is difficult to adjust the height, and the mounting state shown in FIG. 5 (A) and FIG. 5 (B) are difficult.
It tends to be in the mounting state shown in. For this reason, it takes time to be able to position at the correct clamp position. Therefore, as shown in FIG. 6, there is also an apparatus for exhausting the air of the digging stage on which the die pad is mounted by the vacuum pump 9 to suck the die pad on the stage surface by vacuum. In this case, however, the die pad can only be sucked. The floating of inner leads cannot be suppressed. Further, in this case, the air flowing during the vacuum suction removes heat from the die pad portion, lowering the temperature of the die pad and possibly causing defective adhesion.

The present invention has been made in consideration of the above points, and an object thereof is to propose a die bonding apparatus in which defects are less likely to occur as compared with conventional ones.

[0007]

In order to solve such a problem, in the present invention, the surface of the heat adapter (13) is formed by magnetically applying the die pad and the inner lead of the lead frame (4) made of a magnetic material at the time of wire bonding. The electromagnets (11) and (12) attracted to the wire bonding device are provided in the wire bonding apparatus.

Further, in the present invention, at the time of wire bonding, the wind adapter (19) of the mechanical pressing mechanism made of a magnetic material is magnetically applied to the heat adapter (1).
By adsorbing to the surface of 3), the wind clamper (1
Wire bonding of electromagnets (11), (12) for holding the die pad and the inner lead of the non-magnetic lead frame (18) sandwiched between 9) and the heat adapter (13) on the surface of the wind clamper (19). Installed in the device.

[0009]

When the lead frame (4) is a magnetic material, the die pads and inner leads of the lead frame (4) are attracted to the surface of the heat adapter (13) by the magnetic force of the electromagnets (11) and (12). As a result, the lead frame (4) can be accurately clamped without a defect even if the wind clamper, which requires skill for adjustment work, is eliminated.

When the lead frame (18) is made of a non-magnetic material, the magnetic force of the electromagnets (11) and (12) causes the wind clamper (19) to be attracted to the surface of the heat adapter (13). Even if the wind clamper (19) is not installed properly, the lead frame (1
8) can be accurately clamped without any defect.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 10 generally indicates a wire bonding apparatus used for bonding the lead frame 4 containing an iron-based metal material, which is characterized in that the lead frame 4 can be clamped without using a wind clamper. I am trying. Therefore, the wire bonding device 10 uses an electromagnet in which a coil 12 is wound around a U-shaped iron core 11. That is, the lead frame 4 made of an iron-based material is attracted to the heat adapter 13 by the magnetic force of the electromagnet, so that the die pad and the inner lead and the heat adapter 13 are fixed to each other without a gap.

For attachment of the heat adapter 13 to the electromagnet, a positioning pin 11A and four attachment screws 14 are used. As described above, the recessed portion formed on the back surface of the heat adapter 13 and the positioning pin 11A formed on the end surface of the iron core 11 are fitted to each other to simplify the work during assembly. The heater block 8A for heating the heat adapter 13 is fixed in the space surrounded by the U-shaped iron core 13. At this time, a surface of the outer peripheral surface of the heater block 8A that is in contact with the iron core 13 is covered with a heat insulating material 15, and the heater block 8A is covered.
It is devised so that the heat of A does not escape to the iron core 13 and the like.

The bonding operation of the wire bonding apparatus 10 having the above structure will be described with reference to FIG.
First, as shown in FIG. 2 (A), the wire bonding apparatus 10 conveys the lead frame 4 along a rail 16 attached so as to face the heat adapter 13 and positions it at a predetermined position facing the heat adapter 13. To do. At this time, the heat adapter 13 is retracted downward so as not to hinder the conveyance of the lead frame 4. The switch SW is in an open state so that no magnetic force is generated.

When the lead frame 4 is conveyed to a predetermined position, the heater adapter 13 which has been retracted to the lower position is driven upward so that the surface of the lead frame 4 comes into contact with the surface of the heat adapter 13. Be positioned at. In this state, the switch SW is closed and a current is passed through the coil 12. As a result, the iron core 11 and the coil 12 function as an electromagnet to generate a magnetic force, and the die pad and the inner lead are attracted to the surface of the heat adapter 13 and fixed without a gap. At this time, since the die pad and the inner lead are fixed to the heat adapter 13 without a gap, the wire can be bonded in a good condition.

When the bonding work is completed for all the inner leads, the switch SW is opened again. As a result, the magnetic force disappears and the die pad and the inner lead become free with respect to the heat adapter 13. After that, the heat adapter 13 is lowered to the retracted position, and the lead frame 4 is conveyed to the next position along the rail 16.

According to the above structure, the lead frame 4 is attracted to the heat adapter 13 by the magnetic force of the electromagnet, so that the die pad and the inner lead can be securely fixed to the surface of the heat adapter 13 without a gap. . As a result, it is possible to prevent the occurrence of defective products due to defective clamps. Further, in the case of the embodiment, since the wind clamper which requires a delicate adjustment work is not required, anyone can easily carry out the repair work.

Further, in the case of the embodiment, the heat capacity of the entire heating system can be reduced by the absence of the wind clamper, and the lead frame 4 can be efficiently heated. Therefore, the heater 8B may be smaller than the conventional one, and the size of the entire apparatus can be reduced. Further, since the heat capacity is small, the amount of change is small and the heating temperature can be kept more stable than in the conventional case.

In the above-mentioned embodiment, the case where the lead frame 4 contains the iron-based metal is described, but the present invention is not limited to this, and the lead frame 4 does not contain the iron-based metal (that is, non-ferrous metal such as copper). Lead frame 1 (made of metal)
It can also be applied to the case where 8 is fixed on the heat adapter 13. In this case, the wire bonding apparatus 17 of FIG. 3 in which the same parts as those in FIG.
Wind clamper 1 of this wire bonding device 17
9 is used in which the pressing portion of the lead frame 18 has a smaller thickness than the conventional one.

By forming the thin wind clamper 19 from an iron-based metal, when a current is applied to the coil 12 to generate a magnetic force, the wind clamper 19 is deformed along the surface of the heat adapter 13 and the lead frame. 18
Can be pressed against the heat adapter 13 without a gap. By using the thin wind clamper 19 as described above, even the lead frame 18 made of a non-ferrous metal can be pressed against the heat adapter 13 without a defective clamp, and a defective product can be prevented.

In the above embodiment, the case where the lead frame 4 made of iron-based metal is attracted to the surface of the heat adapter 13 only by magnetic force has been described. However, the present invention is not limited to this, and a wind clamper is used. You may use it in combination. In this case, the material of the wind clamper can be applied to both ferrous metal and non-ferrous metal.

[0022]

As described above, according to the present invention, when the lead frame is a magnetic material, the magnetic force of the electromagnet causes the die pad and the inner lead of the lead frame to be attracted to the surface of the heat adapter. As a result, it is possible to realize a wire bonding apparatus that can accurately clamp a lead frame without a defect even without a wind clamper that requires skill in adjustment work.

Further, according to the present invention, when the lead frame is made of a non-magnetic material, the wind clamper is attracted to the surface of the heat adapter by the magnetic force of the electromagnet, so that the mounting state is slightly displaced. Even with a wind clamper, it is possible to realize a wire bonding device that can accurately clamp a lead frame without defects.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a wire bonding apparatus according to the present invention.

FIG. 2 is a side view showing a positional relationship between heat adapters during conveyance and a positional relationship between heat adapters during adsorption.

FIG. 3 is a perspective view showing an embodiment of a wire bonding apparatus according to the present invention.

FIG. 4 is a perspective view showing a conventionally used wire bonding apparatus.

FIG. 5 is a side view for explaining a clamp adjustment failure.

FIG. 6 is a schematic diagram showing a heat adapter having a vacuum suction function.

[Explanation of symbols]

1, 10, 17 ... Die bonding machine, 2, 19 ...
… Wind clamper, 3,13… Heat adapter,
4, 18 ... Lead frame, 5 ... Wind clamper mounting part, 6, 14 ... Mounting screw, 7 ... Angle adjusting screw,
8A ... heater, 8B ... heater block, 9 ... vacuum pump, 11 ... iron core, 12 ... coil, 15 ... heat insulating material, 16 ... rail.

Claims (4)

[Claims] 1. A wire bonding apparatus characterized by comprising an electromagnet for adsorbing a die pad and an inner lead of a lead frame made of a magnetic material to a surface of a heat adapter by magnetic force during wire bonding. 2. A wind clamper for mechanically sandwiching the die pad and the inner lead of the lead frame on the surface of the heat adapter.
The wire bonding apparatus described in. 3. The wire bonding apparatus according to claim 2, wherein the wind clamper is made of a magnetic material. 4. During wire bonding, a wind clamper of a mechanical pressing mechanism made of a magnetic material is attracted to the surface of the heat adapter by a magnetic force so that the wind clamper is not sandwiched between the wind clamper and the heat adapter. A wire bonding apparatus comprising an electromagnet for holding a die pad and an inner lead of a magnetic lead frame on the surface of the wind clamper.